Rifle scope turret with spiral cam mechanism

ABSTRACT

Rifle scope turrets with spiral cam mechanisms include a scope body, a movable optical element defining an optical axis enclosed by the scope body, and a turret having a screw operably connected to the optical element for adjusting the optical axis in response to rotation of the screw. The turret has a spiral cam mechanism engaged thereto. The turret defines first and second stop surfaces positioned for engagement by the spiral cam to limit rotation of the turret. The first stop surface defines a zero position of the screw and the movable optical element. The second stop surface defines a maximum point of displacement of the screw and the moveable optical element. The stop surfaces may be defined by a spiral cam groove in the indexing portion of the turret. The groove may overlap itself at least partially. The turret may be an elevation turret or a windage turret.

FIELD OF THE INVENTION

The present invention relates to a rifle scope turret that uses a spiral cam mechanism to achieve multiple functions: adjustment stops that prevent adjustment of the elevation and windage turrets beyond preset amounts, rotation indicator/counter, and turret locking.

BACKGROUND OF THE INVENTION

A turret is one of two knobs in the outside center part of a riflescope body. Turrets are marked in increments and are used to adjust elevation and windage for points of impact change. Conventional turrets have markings on them that indicate how many clicks of adjustment have been dialed in on the turret, or an angular deviation, or a distance compensation for a given cartridge. A click is one tactile adjustment increment on the windage or elevation turret of a scope.

In order to achieve accurate sighting of objects at greater distances, the downward acceleration on the projectile imparted by gravity is of greater significance. The effect of gravity on a projectile in flight is often referred to as bullet drop because it causes the bullet to drop from the shooters line of sight. For accuracy at longer distances, the sighting components of a gun must compensate for the effect of bullet drop. An adjustment to the angular position of the rifle scope relative to the rifle barrel is made using the elevation turret to compensate for bullet drop.

Conventional elevation turrets allow for multiple rotations in order to enable the scope to compensate for longer-range targets. Unfortunately, conventional turrets typically omit at least one of the following functions: adjustment stops that prevent adjustment of the elevation and windage turrets beyond preset amounts, rotation indicator/counter, or turret locking. As a result, users of conventional turrets may lose track of how many rotations are dialed in if he or she does not carefully count the number of rotations both while dialing away from the zero point and when dialing towards the zero point even when the turret's markings are visible. Furthermore, turrets can be easily humped, and in dark conditions where it may be difficult to see the turret markings, the user may not realize the turrets have been inadvertently adjusted if the turret omits a locking mechanism.

Another difficulty with existing rifle scopes is that certain operating conditions require the user to remember both how many clicks and the direction of rotation needed to return the elevation turret to its zero point from a different setting. When light conditions are poor, such as at twilight, night, or in darkened rooms of buildings, or if it is difficult for the user to hear or feel the clicks, it is very easy for the user to lose track of what adjustment is needed to return to the zero point. Under such conditions, the markings may not be sufficiently visible and the absence of a tactile rotation indicator is keenly felt. This is particularly significant for police and military users of firearms, who in the course of their duties may very likely be confronted with a threat under poor lighting conditions. In addition, hunters may hunt at twilight or in deep shade.

Because of the need for compact riflescope components, markings are necessarily small, making them difficult to read under borderline conditions. White this may be a concern when making fine adjustments, it is of greater concern when a user must make large changes involving several revolutions of a knob, which may lead to an error in the number of revolutions made.

Therefore, a need exists for a new and improved rifle scope with adjustment stops that prevents adjustment of the elevation and windage turrets beyond preset amounts. There is also a need for visual and tactile indication of how many rotations have been dialed in on the elevation turret. Finally, there is a need for a turret locking mechanism so the user can be assured that the turret is still in its last used position. In this regard, the various embodiments of the present invention substantially fulfill at least some of these needs. In this respect, the spiral cam mechanism according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of preventing adjustment of a turret beyond a preset amount, giving the user an indication of how many rotations have been dialed on the turret, and giving the user the ability to lock the turret.

SUMMARY OF THE INVENTION

The present invention provides an improved rifle scope with adjustment stops, rotation indicator, and locking mechanism, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide an improved rifle scope with adjustment stops, rotation indicator, and locking mechanism that has all the advantages of the prior art mentioned above.

To attain this, the preferred embodiment of the present invention essentially comprises a scope body, a movable optical element defining an optical axis enclosed by the scope body, and a turret having a screw operably connected to the optical element for adjusting the optical axis in response to rotation of the screw. The turret has a spiral cam mechanism engaged thereto. The turret defines first and second stop surfaces positioned for engagement by the spiral cam to limit rotation of the turret. The first stop surface defines a zero position of the screw and the movable optical element. The second stop surface defines a maximum point of displacement of the screw and the moveable optical element. The stop surfaces may be defined by a spiral cam groove in the indexing portion of the turret. The spiral cam groove may overlap itself at least partially. The turret may be an elevation turret or a windage turret. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the current embodiment of the rifle scope with adjustment stops constructed in accordance with the principles of the present invention.

FIG. 2 is a top perspective exploded view of the elevation turret screw subassembly of the present invention.

FIG. 3 is a top perspective exploded view of the elevation turret screw subassembly and turret housing of the present invention.

FIG. 4 is a top perspective view of the elevation turret chassis and elevation indicator of the present invention.

FIG. 5A is a top perspective view of the elevation cam disc of the present invention.

FIG. 5B is a bottom perspective view of the elevation cam disc of the present invention.

FIG. 6 is a top view of the elevation cam disc inserted into the elevation turret chassis of the present invention with the elevation cam disc rendered partially transparent.

FIG. 7A is a top perspective exploded view of the elevation turret chassis subassembly of the present invention.

FIG. 7B is a side sectional view of the elevation turret chassis subassembly of the present invention.

FIG. 8A is a top perspective exploded view of the elevation turret chassis subassembly, elevation turret screw subassembly, and turret housing of the present invention.

FIG. 8B is a side sectional view of the elevation turret chassis subassembly, elevation turret screw subassembly, and turret housing of the present invention.

FIG. 9A is a top perspective exploded view of the elevation micro adjuster and elevation outer knob of the present invention.

FIG. 9B is a side sectional view of the elevation micro adjuster, elevation outer knob, elevation turret chassis subassembly, and elevation turret screw subassembly of the present invention.

FIG. 10 is a top perspective view of the windage turret chassis of the present invention.

FIG. 11 is a bottom perspective view of the windage cam disc of the present invention.

FIG. 12 is a side sectional view of the windage turret of the present invention.

FIG. 13 is a side sectional view of the rifle scope with adjustment stops of FIG. 1.

FIG. 14A is a rear view of the rifle scope with adjustment stops of FIG. 1 with the elevation turret in the locked position.

FIG. 14B is a rear view of the rifle scope with adjustment stops of FIG. 1 with the elevation turret in the unlocked position.

FIG. 15A is a rear view of the rifle scope with adjustment stops of FIG. 1 with the elevation turret having made one rotation.

FIG. 15B is a rear view of the rifle scope with adjustment stops of FIG. 1 with the elevation turret having made two rotations.

The same reference numerals refer to the same parts throughout the various figures.

DESCRIPTION OF THE CURRENT EMBODIMENT

A preferred embodiment of the rifle scope with spiral cam mechanism of the present invention is shown and generally designated by the reference numeral 10.

FIG. 1 illustrates the improved rifle scope with spiral cam mechanism 10 of the present invention. More particularly, the rifle scope 10 has a scope body 12 that encloses a movable optical element 248 (shown in FIG. 13), which is an erector tube. The scope body is an elongate tube having a larger opening at its front 14 and a smaller opening at its rear 16. An eyepiece 18 is attached to the rear of the scope body, and an objective lens 20 is attached to the front of the scope body. The center axis of the movable optical element defines the optical axis 506 of the rifle scope.

An elevation turret 22 and a windage turret 24 are two knobs in the outside center part of the scope body 12. They are marked in increments by indicia 34 and 24 on their perimeters 30 and 32 and are used to adjust the elevation and windage of the movable optical element 248 for points of impact change. These knobs protrude from the turret housing 36. The turrets are arranged so that the elevation turret rotation axis 26 is perpendicular to the windage turret rotation axis 28. Indicia typically include tick marks, each corresponding to a click, and larger tick marks at selected intervals, as well as numerals indicating angle of adjustment or distance for bullet drop compensation.

The movable optical element 248 is adjusted by rotating the turrets one or more clicks. A click is one tactile adjustment increment on the windage or elevation turret of the rifle scope, each of which corresponds to an indicium 34 and 24. In the current embodiment, one click changes the scope's point of impact by 0.1 mrad.

FIG. 2 illustrates the improved turret screw subassembly 88 of the present invention. More particularly, the turret screw subassembly consists of a turret screw 38, a turret screw base 60, a friction pad 86, and various fasteners. The turret screw is a cylindrical body made of brass in the current embodiment. The top 40 of the turret screw defines a slot 48, and two opposing cam slots 46 run from the top part way down the side 44. Two O-ring grooves 50 and 52 are on the side located below the cam slots. The bottom 42 of the turret screw has a reduced radius portion 56 that defines a ring slot 54. The ring slot 54 receives a retaining ring 84, and the bottom 42 receives the shaft 306 of the friction pad 86. The side of the turret screw immediately below the O-ring groove 52 and above the ring slot 54 is a threaded portion 58. In the current embodiment, the slot 48 is shaped to receive a straight blade screwdriver, but could be shaped to receive a hex key or any other suitable type of driver.

The turret screw base 60 is a disc-shaped body made of brass in the current embodiment. A cylindrical collar 66 rises from the center of the top 62 of the turret screw base. The collar has a turret screw bore 68 with threads 70. The exterior of the collar defines a set screw V-groove 78 above the top of the turret screw base, an O-ring groove 76 above the set screw V-groove, an O-ring groove 74 above the O-ring groove 76, and a ring slot 72 above the O-ring groove 74. The turret screw base has three mount holes 82 with smooth sides and a shoulder that receive screws 80.

FIG. 3 illustrates the improved turret screw subassembly 88 and turret housing 36 of the present invention. More particularly, the turret screw subassembly 88 is shown assembled and in the process of being mounted on the turret housing 36. The top 92 of the turret housing defines a recess 94. Three mount holes 96 with threads 98 and a smooth central bore 508 are defined in the top of the turret housing within the recess.

The threads 70 of the turret screw bore 68 are fine such that the turret screw bore may receive the threads 58 on the turret screw 38. The retaining ring 84 limits upward travel of the turret screw so that the turret screw cannot be inadvertently removed from the turret screw bore.

When the turret screw subassembly 88 is mounted on the turret housing 36, screws 80 are inserted into the mount holes 82 and protrude from the bottom 64 of the turret screw base 60. The screws are then screwed into the mount holes 96 in the turret housing to mount the turret screw base to the scope housing. Subsequently, the turret screw base remains in a fixed position with respect to the scope body 12 when the elevation turret 22 is rotated. This essentially makes the turret screw base functionally unitary with the scope body, and the turret screw base is not intended to be removed or adjusted by the user. The smooth central bore 508 in the top of the turret housing permits passage of the friction pad 86 and the bottom 42 of the turret screw into the scope body.

FIG. 4 illustrates the improved elevation turret chassis 100 of the present invention. More particularly, the top 110 of the elevation turret chassis has an interior perimeter 102 with a relief cut 240 adjacent to the floor 264, a toothed surface 108 above the relief cut, a lower click groove 106 above the toothed surface, and an upper click groove 104 above the lower click groove. The relief cut is for the tool that cuts the toothed surface. The floor defines a smooth central bore 120 and a slot 122. The smooth central bore permits passage of the friction pad 86 and the bottom 42 of the turret screw through the turret chassis.

The exterior perimeter 112 of the turret chassis 100 defines an O-ring groove 244. Near the bottom 116 of the turret chassis, the exterior perimeter widens to define a shoulder 114. Three holes 118 with threads 158 communicate from the exterior perimeter through the turret chassis to the smooth bore 120. In the current embodiment, the turret chassis is made of steel.

The slot 122 in the floor 264 of the turret chassis 100 communicates with a hole 124 in the exterior perimeter 112 of the turret chassis. The hole 124 receives an elevation indicator 136. The rear 140 of the turret indicator defines a cam pin hole 154. The front 138 of the elevation indicator has two stripes 148 and 150 and an O-ring groove 152. The stripe 148 divides a first position 142 from a second position 144. The stripe 150 divides a second position 144 from a third position 146. In the current embodiment, the elevation indicator is made of painted black steel, and the stripes are white lines that do not glow, but which could be luminous in an alternative embodiment.

The cam pin hole 154 receives the bottom 134 of a cam pin 126. In the current embodiment, the cam pin is a cylindrical body made of steel. The top 128 of the cam pin has a reduced radius portion 130 that defines a shoulder 132. The reduced radius portion of the cam pin protrudes upward through the slot 122 above the floor 264 of the turret chassis 100.

FIGS. 5A and 5B illustrate improved elevation cam disc 160 of the present invention. More particularly, the elevation cam disc is made of steel with a top face 162 and a bottom face 164. The top has a reduced radius portion 166 that defines a shoulder 168 around the exterior perimeter 170 of the elevation cam disc. The top also defines three mount holes 180 with threads 182. A reduced radius central portion 176 defines a shoulder 172 and a smooth central bore 178. The smooth central bore permits passage of the friction pad 86 and the bottom 42 of the turret screw through the elevation cam disc.

A radial clicker channel 186 in the top 162 of the exterior perimeter 170 receives a clicker 188 that reciprocates in the channel, and is biased radially outward. The front, free end 190 of the clicker protrudes from the exterior perimeter. In the current embodiment, the clicker has a wedge shape with a vertical vertex parallel to the axis of rotation of the turret and is made of steel.

The bottom 164 of the elevation cam disc 160 is a planar surface perpendicular to the elevation turret rotation axis 26 that defines a recessed spiral channel 184. The spiral channel terminates in a zero stop surface 198 when traveled in a clockwise direction and terminates in an end of travel stop surface 200 when traveled in a counterclockwise direction. When traveled in a counterclockwise direction, the spiral channel defines a first transition 194 and a second transition 196 when the spiral channel begins to overlap itself for the first time and second time, respectively. The spiral channel is adapted to receive the reduced radius portion 130 of the cam pin 126. The spiral channel and the stop surfaces are integral to the elevation cam disc and are not adjustable.

FIG. 6 illustrates the improved elevation cam disc 160 and improved turret chassis 100 of the present invention. More particularly, the elevation cam disc is shown installed in the turret chassis. The spiral channel 184 receives the reduced radius portion 130 of the cam pin 126. The clicker 188 protrudes from the clicker channel 186 in the exterior perimeter 170 of the elevation cam disc. A spring 202 at the rear 192 of the clicker outwardly biases the clicker such that the clicker is biased to engage with the toothed surface 108 on the interior perimeter 102 of the turret chassis. When the elevation cam disc rotates as the elevation turret 22 is rotated when changing elevation settings, the clicker travels over the toothed surface, thereby providing a rotational, resistant force and making a characteristic clicking sound.

In the preferred embodiment, the toothed surface 108 has 100 teeth, which enables 100 clicks per rotation of the elevation turret 22. The spiral channel 184 is formed of a several arcs of constant radius that are centered on the disc center, and extend nearly to a full circle, and whose ends are joined by transition portions of the channel, so that one end of the inner arc is connected to the end of the next arc, and so on to effectively form a stepped spiral. This provides for the indicator to remain in one position for most of the rotation, and to transition only in a limited portion of turret rotation. In an alternative embodiment the spiral may be a true spiral with the channel increasing in its radial position in proportion to its rotational position. In the most basic embodiment, the channel has its ends at different radial positions, with the channel extending more than 360 degrees, the ends being radially separated by material, and allowing a full 360 degree circle of rotation with the stop provided at each channel end.

The elevation turret 22 is positioned at the indicium 34 corresponding to 0° of adjustment when the cam pin 126 is flush with the zero stop surface 198. In the preferred embodiment, the spiral channel 184 holds the cam pin 126 in a circular arc segment at a constant distance from the rotation axis 26 until the elevation turret has rotated 9 mrad (324°). The first transition 196 occurs as the elevation turret rotates counterclockwise from 9 mrad (324°) to 10 mrad (360°). During the first transition, the spiral channel shifts the cam pin 126 towards the exterior perimeter 170 so the spiral channel can begin overlapping itself. As the elevation turret continues its counterclockwise rotation, the spiral channel holds the cam pin 126 in a circular arc segment at a constant further distance from the rotation axis 26 until the elevation turret has rotated 19 mrad (684°). The second transition 196 occurs as the elevation turret rotates counterclockwise from 19 mrad (684°) to 20 mrad (720°). During the second transition, the spiral channel shifts the cam pin 126 even further towards the exterior perimeter 170 so the spiral channel can overlap itself a second time. As the elevation turret continues its counterclockwise rotation, the spiral channel holds the cam pin 126 in a circular arc segment at a constant even further distance from the central bore 178 until the elevation turret has rotated 28.5 mrad (1026°). At that time, the cam pin is flush with the end of travel stop surface 200, and further counterclockwise rotation of the elevation turret and elevation adjustment are prevented. In the current embodiment, the first and second transitions are angled at about 36° (10% of the rotation) to enable adequate wall thickness between the concentric circular arc segments about the rotation axis 26 of the spiral channel. The cam pin diameter determines the overall diameter of the turret. Because there are three rotations, any increase in diameter will be multiplied by three in how it affects the overall turret diameter. In the preferred embodiment, a cam pin diameter of 1.5 mm provides adequate strength while remaining small enough to keep the overall diameter of the turret from becoming too large.

FIGS. 7A and 713 illustrate the elevation turret chassis subassembly 230 of the present invention. More particularly, the turret chassis subassembly is assembled by inserting a locking gear 206 into the turret chassis 100 on top of the elevation cam disc 160. The elevation turret chassis subassembly is shown in the locked position in FIG. 7B.

The locking gear 206 has a top 208 and a bottom 210. The top 208 defines three mount holes 216 with threads 218. The locking gear also defines three smooth mount holes 220 and a central smooth bore 222. The bottom 210 of the locking gear defines a toothed surface 214. The toothed surface 214 extends downward below the bottom 210 of the locking gear to encircle the reduced radius portion 166 of the top 162 of the elevation cam disc 160 when the turret chassis subassembly is assembled. In the current embodiment, the toothed surface 214 has 100 teeth to mesh precisely with the 100 teeth of the toothed surface 108 on the interior perimeter 102 of the turret chassis 100 when the elevation turret 22 is locked.

Four ball bearings 226 protrude outwards from bores 232 in the exterior perimeter 212 located between the toothed surface and the top. Springs 400 behind the ball bearings outwardly bias the ball bearings such that the ball bearings are biased to engage with the upper click groove 104 and lower click groove 106 on the interior perimeter 102 of the turret chassis 100. When the locking gear rises and towers as the elevation turret 22 is unlocked and locked, the ball bearings travel between the lower and upper click grooves, thereby providing a vertical, resistant force and making a characteristic clicking sound.

When the turret chassis subassembly 230 is assembled, screws 224 are inserted into the mount holes 220 and protrude from the bottom 210 of the locking gear 206. The screws are then screwed into the mount holes 180 in the top 162 of the elevation cam disc 160 to mount the locking gear to the elevation cam disc. Subsequently, the locking gear remains in a fixed rotational position with respect to the elevation cam disc when the elevation turret 22 is unlocked and rotated. The heads 234 of the screws 224 are much thinner than the depth of the mount holes 220 from the top 208 of the locking gear to the shoulders 236. The screws 224 have shoulders 228 that contact the top 162 of the elevation cam disc 160 when the screws are secured. As a result, the locking gear is free to be raised until the heads of the screws contact the shoulders 236 and to be lowered until the bottom of the locking gear contacts the top of the elevation cam disc. This vertical movement is sufficient for the toothed surface 214 of the locking gear to be raised above the toothed surface 108 of the turret chassis 100, thereby enabling the elevation turret to be unlocked and free to rotate.

FIGS. 8A and 8B illustrate the elevation turret chassis subassembly 230, turret screw subassembly 88, and turret housing 36 of the present invention. More particularly, the turret chassis subassembly is shown assembled and in the process of being mounted on the turret screw subassembly in FIG. 5A and mounted on the turret screw subassembly in FIG. 8B.

When the elevation turret chassis subassembly 230 is mounted on the turret screw subassembly 88, the top 40 of the turret screw 38 and the collar 66 of the turret screw base 60 pass upwards through the smooth central bore 120 of the turret chassis 100, the smooth central bore 178 of the elevation cam disc 160, and the smooth central bore 222 of the locking gear 206. A retaining ring 246 is received by the ring slot 72 in the collar to prevent the elevation turret chassis subassembly from being lifted off of the turret screw subassembly. Three recesses 244 in the bottom 116 of the turret chassis receive the heads of the screws 80 that protrude from the top 62 of the turret screw base 60 so the bottom 116 of the turret chassis can sit flush against the top 92 of the turret housing 36.

FIGS. 9A and 9B illustrate improved elevation turret 22 with the top cap 308 removed. More particularly, the outer knob 268 is inserted over the top 110 of the turret chassis 100 so that the bottom 272 of the outer knob rests against the shoulder 114 of the turret chassis. The top 270 of the outer knob defines a recess 274 with threads 276. The top of the outer knob also defines three mount holes 280 and a smooth central bore 284. Each of the mount holes 280 receives a screw 282. The screws 282 are screwed into mount holes 216 in the top 208 of the locking gear 206. The perimeter 30 of the outer knob has three holes 300 in the knurled portion 310. The holes 300 communicate with the central bore 284.

The recess 274 of the outer knob 268 receives an elevation micro adjuster 266 when the elevation turret 22 is assembled. The micro adjuster is a disc with a smooth central bore 292 and a downward facing central shaft 286. The shaft defines an O-ring groove 296 immediately below the disc-shaped portion of the micro adjuster. The shaft defines a V-groove 294 immediately below the O-ring groove, and two cam pin holes 288 immediately below the V-groove. Each of the cam pin holes receives a cam pin 290. When the elevation turret 22 is assembled, the shaft 286 is received by the bore 284 in the outer knob 268 and by the bore 222 in the locking gear. The cam pins are received by the cam shafts 46 in the turret screw 38.

The micro adjuster 266 is used to provide infinite adjustability of the point of aim instead of limiting the point of aim to coincide with turret click positions. Indicia 290 on the micro adjuster rotate to indicate how much adjustment is being made. A flat blade screwdriver is inserted into the slot 48 on the top 40 of the turret screw 38 to make the adjustment once the outer knob is disengaged from the V-groove 294 in the micro adjuster.

O-rings 298, 238, 242, 508, 252, 260, 262, 256, 258, and 244 seal the elevation turret 22 to protect its components from the elements.

FIG. 10 illustrates the improved windage turret chassis 338 of the present invention. More particularly, the top 334 of the windage turret chassis has an interior perimeter 340 with a relief cut 362 adjacent to the floor 364, a toothed surface 342 above the relief cut, a tower click groove 360 above the toothed surface, and an upper click groove 358 above the lower click groove. The floor defines a smooth central bore 368 and a slot 368. The smooth central bore permits passage of the friction pad 478 and the bottom 468 of the turret screw 446 through the turret chassis.

The exterior perimeter 346 of the turret chassis 338 defines a V-groove 352. Near bottom 350 of the turret chassis, the exterior perimeter widens to define a shoulder 348. Three holes 354 with threads 356 communicate from the exterior perimeter through the turret chassis to the smooth bore 366. In the current embodiment, the turret chassis is made of steel.

The slot 122 in the floor 264 of the turret chassis 338 receives the bottom 372 of a cam pin 370. In the current embodiment, the cam pin is a cylindrical body made of steel. The top 376 of the cam pin has a reduced radius portion 378 that defines a shoulder 374. The reduced radius portion of the cam pin protrudes upward through the slot 368 above the floor 364 of the turret chassis 338.

FIG. 11 illustrates improved windage cam disc 322 of the present invention. More particularly, the windage cam disc is made of steel with a top 510 and a bottom 326. The top has a reduced radius portion 514 that defines a shoulder 560 around the exterior perimeter 518 of the elevation cam disc. The top also defines three mount holes 522 with threads 524. A reduced radius central portion 502 defines a shoulder 526 and a smooth central bore 328. The smooth central bore permits passage of the friction pad 478 and the bottom 468 of the turret screw 446 through the windage cam disc.

A clicker channel 512 in the top 510 of the exterior perimeter 518 receives a clicker 334. The front 336 of the clicker protrudes from the exterior perimeter. In the current embodiment, the clicker is made of steel.

The bottom 326 of the windage cam disc 322 is a planar surface perpendicular to the windage turret rotation axis 28 that defines a recessed spiral channel 324. The spiral channel terminates in an end of travel stop surface 330 when traveled in a clockwise direction and terminates in an end of travel stop surface 332 when traveled in a counterclockwise direction. When traveled in a counterclockwise direction, the spiral channel gradually moves outwards from the bore 328 so the spiral channel can slightly overlap itself. The spiral channel is adapted to receive the reduced radius portion 130 of the cam pin 126. The spiral channel and the stop surfaces are integral to the elevation cam disc and are not adjustable. To provide a full 360° of rotation, the center points of the semi-circular ends of the channel are at the same rotational position on the disc, at different radial distances from the center of the disc.

When the windage cam disc 322 is installed in the turret chassis 338, the spiral channel 324 receives the reduced radius portion 378 of the cam pin 370. The clicker 334 protrudes from the clicker channel 512 in the exterior perimeter 518 of the windage cam disc. A spring 412 at the rear 410 of the clicker outwardly biases the clicker such that the clicker is biased to engage with the toothed surface 342 on the interior perimeter 340 of the turret chassis. When the windage cam disc rotates as the windage turret 24 is rotated when changing windage settings, the clicker travels over the toothed surface, thereby providing a rotational, resistant force and making a characteristic clicking sound.

In the current embodiment, the toothed surface 342 has 100 teeth, which enables 100 clicks per rotation of the windage turret 24. The windage turret 24 is positioned at the indicium 90 corresponding to 0° of adjustment when the cam pin 370 is located at the midpoint 328 of the spiral channel 324. The spiral channel holds the cam pin 126 in an arc segment at a constantly increasing distance from the rotation axis 28. The spiral channel 324 permits one-half of a revolution either clockwise or counterclockwise from the zero point 328, which is 5 mrad in the current embodiment. At that time, the cam pin is flush with an end of travel stop surface, and further rotation of the windage turret and windage adjustment are prevented. The spiral channel 324 could be reconfigured to allow various other mrads of travel from the zero point 328.

FIG. 12 illustrates the improved windage turret 24 of the present invention. More particularly, the windage turret 24 is substantially identical in construction to the elevation turret 22 except for changes to the spiral cam disc and elimination of the elevation indicator.

The turret screw subassembly 528 consists of a turret screw 446, a turret screw base 490, a friction pad 478, and various fasteners. The turret screw is a cylindrical body made of brass in the current embodiment. The top 442 of the turret screw defines a slot 444, and two opposing cam slots run from the top part way down the side 530. Two O-ring grooves 464 and 494 are on the side located below the cam slots. The bottom 468 of the turret screw has a reduced radius portion 470 that defines a ring slot 472. The ring slot 472 receives a retaining ring 476, and the bottom 468 receives the shaft 480 of the friction pad 478 in a bore 474. The side of the turret screw immediately below the O-ring groove 494 and above the ring slot 472 is a threaded portion 492. In the current embodiment, the slot 444 is shaped to receive a straight blade screwdriver.

The turret screw base 490 is a disc-shaped body made of steel in the current embodiment. A cylindrical collar 498 rises from the center of the top 532 of the turret screw base. The collar has a turret screw bore 532 with threads 534. The exterior of the collar defines a set screw V-groove 458 above the top of the turret screw base, an O-ring groove 456 above the set screw V-groove, an O-ring groove 454 above the O-ring groove 456, and a ring slot 452 above the O-ring groove 456. The turret screw base has three mount holes 536 with smooth sides and a shoulder that receive screws 486.

The threads 534 of the turret screw bore 532 are fine such that the turret screw bore may receive the threads 492 on the turret screw 446. The retaining ring 476 limits upward travel of the turret screw so that the turret screw cannot be inadvertently removed from the turret screw bore.

A locking gear 548 is inserted into the turret chassis 338 on top of the windage cam disc 322. The windage turret 24 is shown in the locked position in FIG. 12. The locking gear has a top 402 and a bottom 326. The top 402 defines three mount holes 538 with threads 540. The locking gear also defines three smooth mount holes 426 and a central smooth bore 500. The bottom 326 of the locking gear defines a toothed surface 542. The toothed surface 542 extends downward below the bottom 326 of the locking gear to encircle the reduced radius portion 514 of the top 510 of the windage cam disc 322 when the turret chassis subassembly 544 is assembled, in the current embodiment, the toothed surface 542 has 100 teeth to mesh precisely with the 100 teeth of the toothed surface 342 on the interior perimeter 340 of the turret chassis 338 when the windage turret 24 is locked.

Four ball bearings 404 protrude outwards from bores 408 in the exterior perimeter 546 located between the toothed surface and the top. Springs 406 behind the ball bearings outwardly bias the ball bearings such that the ball bearings are biased to engage with the upper click groove 358 and lower click groove 360 on the interior perimeter 340 of the turret chassis 338. When the locking gear rises and lowers as the windage turret 24 is unlocked and locked, the ball bearings travel between the lower and upper click grooves, thereby providing a vertical, resistant force and making a characteristic clicking sound.

When the turret chassis subassembly 544 is assembled, screws 422 are inserted into the mount holes 426 and protrude from the bottom 326 of the locking gear 548. The screws are then screwed into the mount holes 522 in the top 510 of the windage cam disc 322 to mount the locking gear to the windage cam disc. Subsequently, the locking gear remains in a fixed rotational position with respect to the windage cam disc when the windage turret 24 is unlocked and rotated. The heads 424 of the screws 422 are much thinner than the depth of the mount holes 426 from the top 402 of the locking gear to the shoulders 550. The screws 422 have shoulders 428 that contact the top 510 of the windage cam disc 322 when the screws are secured. As a result, the locking gear is free to be raised until the heads of the screws contact the shoulders 550 and to be lowered until the bottom of the locking gear contacts the top of the windage cam disc. This vertical movement is sufficient for the toothed surface 542 of the locking gear to be raised above the toothed surface 342 of the turret chassis 338, thereby enabling the windage turret to be unlocked and free to rotate.

When the windage turret chassis subassembly 544 is mounted on the turret screw subassembly 528, the top 442 of the turret screw 446 and the collar 498 of the turret screw base 490 pass upwards through the smooth central bore 366 of the turret chassis 338, the smooth central bore 328 of the windage cam disc 322, and the smooth central bore 500 of the locking gear 548. A retaining ring 450 is received by the ring slot 452 in the collar to prevent the windage turret chassis subassembly from being lifted off of the turret screw subassembly. Three recesses 552 in the bottom 414 of the turret chassis receive the heads of the screws 486 that protrude from the top 532 of the turret screw base 490 so the bottom 414 of the turret chassis can sit flush against the top of the turret housing 36. O-rings 488 seal the screws 486 within mount holes 536. An O-ring groove 482 in the bottom 554 of the turret screw base receives an O-ring 484 to seal the bottom of the turret screw base against the top of the turret housing 36.

The outer knob 380 is inserted over the top 334 of the turret chassis 338 so that the bottom 556 of the outer knob rests against the shoulder 348 of the turret chassis. The top 392 of the outer knob defines a recess 558 with threads 382. The top of the outer knob also defines three mount holes 560 and a smooth central bore 562. Each of the mount holes 560 receives a screw 398. The screws 398 are screwed into mount holes 538 in the top 402 of the locking gear 548. The perimeter 32 of the outer knob has three holes 384 in the knurled portion 312. The holes 384 communicate with the central bore 562.

The recess 558 of the outer knob 380 receives an elevation micro adjuster 388 when the windage turret 24 is assembled. The micro adjuster is a disc with a smooth central bore 390 and a downward facing central shaft 448. The shaft defines an O-ring groove 394 immediately below the disc-shaped portion of the micro adjuster. The shaft defines a V-groove 392 immediately below the O-ring groove, and two cam pin holes immediately below the V-groove. Each of the cam pin holes receives a cam pin. When the windage turret 24 is assembled, the shaft 448 is received by the bore 562 in the outer knob 380 and by the bore 500 in the locking gear. The cam pins are received by the cam shafts in the turret screw 446.

The micro adjuster 388 is used to provide infinite adjustability of the point of aim instead of limiting the point of aim to coincide with turret click positions. Indicia on the micro adjuster rotate to indicate how much adjustment is being made. A flat blade screwdriver is inserted into the slot 444 on the top 442 of the turret screw 446 to make the adjustment once the outer knob is disengaged from the V-groove 392 in the micro adjuster.

O-rings 440, 396, 460, 462, 464, 496, 436, 520, 484, 488, and 432 seal the windage turret 24 to protect its components from the elements.

FIGS. 13-15B illustrate improved rifle scope turret with spiral cam mechanism 10 of the present invention. More particularly, the rifle scope 10 is shown in use. FIGS. 14A and 14B show the elevation turret 22 in the locked and unlocked positions, respectively. The elevation turret is unlocked by raising it parallel to the rotation axis 26. This upward motion disengages the toothed surface 214 of the locking gear 206 from the toothed surface 108 of the turret chassis 100. The elevation turret is then free to rotate to the extent permitted by the spiral channel 184 in the elevation cam disc 160. Lowering the elevation turret engages the toothed surface of the locking gear 206 with the toothed surface 108 of the turret chassis. This downward motion returns the elevation turret to the locked position.

When “0” on the outer knob 268 is facing the user, the cam pin 126 is resting against the zero stop surface 198, which prevents any further downward adjustment of the turret screw 38. Zero on the outer knob is the distance the rifle scope 10 is sighted in at when no clicks have been dialed in on the elevation turret and references the flight of the projectile. If the rifle scope is sighted in at 200 yards, it is said to have a 200 yard zero.

When the elevation turret 22 is unlocked, the user rotates the elevation turret counterclockwise for longer range shots than the sight-in distance of the rifle scope 10. Rotation of the turret adjusts the amount of the turret screw 38 that extends from the bottom of the turret. As is shown in FIG. 13, the turret applies a downward force in the form of elevation pressure to the moveable optical element 248 via the friction pad 86. The windage turret 24 applies a sideways force in the form of windage pressure to the movable optical element via the friction pad 478. These forces are balanced by a biasing spring pressure applied to the moveable optical element by a biasing spring at an angle of about 135° with respect to both the elevation pressure and the windage pressure.

Once a full revolution is made on the elevation turret 22, the elevation indicator 136 pops out from hole 124 in the exterior perimeter 112 of the turret chassis 100. The position of the elevation indicator after one revolution is shown in FIG. 15A. The first position 142, stripe 148, and second position 144 are visible. After a second revolution is made on the elevation turret, the elevation indicator extends further outwards as shown in FIG. 15B. The stripe 150 and a portion of the third position 146 are newly visible. When the user dials the turret back down by rotating the turret clockwise, the indicator retracts back into the turret chassis. As a result, the indicator provides both visual and tactile indication to the user of which of the nearly three revolutions the elevation turret is on.

The windage turret functions substantially identically to the elevation turret except for lacking an elevation indicator.

While a current embodiment of the rifle scope with adjustment stops has been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fail within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, failing within the scope of the invention. 

I claim:
 1. A rifle scope comprising: a scope body; a movable optical element defining an optical axis connected to the scope body; a turret having a screw defining a screw axis and operably connected to the optical element for adjusting the optical axis in response to rotation of the screw; a stop element connected to the screw; the stop element defining a guide surface wrapping about the screw axis and terminating at first and second ends; a cam follower element connected to the body and operable to engage the guide surface, and to engage the first and second ends, the engagement of the first and second ends defining the rotational limits of the turret; and wherein the first stop surface and the second stop surface are at different radial distances from the screw axis.
 2. The rifle scope of claim 1 wherein the guide surface is defined by a channel.
 3. The rifle scope of claim 2 wherein the stop element has a planar surface perpendicular to the screw axis, and the channel is defined in the planar surface.
 4. The rifle scope of claim 1 wherein the guide surface includes a plurality of concentric arcs each centered on the screw axis and substantially encompassing the axis, the guide surface including a transition segment connecting one end of a first one of the arcs to an end of a second one of the arcs, such that a stepped spiral is effectively formed.
 5. A rifle scope with spiral cam mechanism comprising: a scope body; a movable optical element defining an optical axis connected to the scope body; a turret having a screw operably connected to the optical element for adjusting the optical axis in response to rotation of the screw; the spiral cam mechanism having a stop element engaged thereto; the spiral cam mechanism defining a first stop surface positioned for engagement by the turret stop element to limit rotation of the turret, such that the position at which the stop element engages the first stop surface defines a zero position of the screw and the movable optical element; the turret defining a second stop surface positioned for engagement by the turret stop element to limit rotation of the turret, such that the position at which the stop element engages the second stop surface defines a maximum point of displacement of the screw and the moveable optical element; wherein the first stop surface and second stop surface are connected by a channel; wherein the channel overlaps itself at least partially; the turret having an indexing portion frictionally engaged with the stop surfaces.
 6. The rifle scope of claim 5: wherein the indexing portion of the turret comprises a rotating element; wherein the stop surfaces are recessed portions of the turret; wherein rotation of the indexing portion in a first direction causes the stop surfaces to move in the first direction; wherein responsive to the stop element encountering the first stop surface, further rotation of the indexing portion in the first direction is prevented.
 7. The rifle scope of claim 6: wherein rotation of the indexing portion in a second direction causes the stop surfaces to move in the second direction; wherein responsive to the stop element encountering the second stop surface, further rotation of the indexing portion in the second direction is prevented.
 8. The rifle scope of claim 5 wherein the stop element is a cam pin.
 9. The rifle scope of claim 8 further comprising an elevation indicator connected to the cam pin, wherein the elevation indicator moves outwards from the turret each time the turret undergoes a full revolution between the first stop surface and the second stop surface.
 10. A rifle scope with spiral cam turret mechanism: a scope body; a movable optical element defining an optical axis connected to the scope body; an elevation turret having a screw operably connected to the optical element for adjusting the optical axis in response to rotation of the screw; the turret having a knob operably connected to the screw to adjust the position of the screw; the turret having an indexing portion engaged to the knob; the turret having a stop element; the indexing portion of the turret defining a first stop surface positioned for engagement by the turret stop element to limit rotation of the turret, such that the position at which the stop element engages the first stop surface defines a first limiting position of the screw and the movable optical element; the indexing portion of the turret defining a second stop surface positioned for engagement by the turret stop element to limit rotation of the turret, such that the position at which the stop element engages the second stop surface defines a second limiting position of the screw and the moveable optical element.
 11. The rifle scope of claim 10: wherein the indexing portion of the turret comprises a rotating element; wherein the turret base comprises a fixed element; wherein the stop surfaces are defined by a groove in the indexing portion of the turret; wherein rotation of the indexing portion in a first direction causes the stop surfaces to move in the first direction; and wherein responsive to the stop element encountering the first stop surface, further rotation of the indexing portion in the first direction is prevented.
 12. The rifle scope of claim 11: wherein rotation of the indexing portion in a second direction causes the stop surfaces to move in the second direction; wherein responsive to the stop element encountering the second stop surface, further rotation of the indexing portion in the second direction is prevented.
 13. The rifle scope of claim 11: wherein the indexing portion of the turret comprises a clicker; wherein the turret comprises a toothed surface; and wherein the clicker engages with the toothed surface to produce a click stop indexing action.
 14. The rifle scope of claim 13, further comprising indicia on the outer knob, wherein each indicium corresponds to a click stop position.
 15. The rifle scope of claim 11, wherein the groove overlaps itself at least partially.
 16. The rifle scope of claim 11, wherein the groove comprises multiple circular arc segments concentric on a central axis, wherein the circular arc segments are joined by angular transition segments.
 17. The rifle scope of claim 16, wherein the stop element is a cam pin received by the groove.
 18. The rifle scope of claim 17, further comprising an elevation indicator connected to the cam pin, wherein the elevation indicator moves outwards from the turret each time the cam pin passes through an angular transition segment.
 19. The rifle scope of claim 10, wherein the turret is an elevation turret.
 20. The rifle scope of claim 10, wherein the turret is a windage turret. 